Expansion plug and installation means and method



Dec. 3, 1968 P. .1. HUNCKLER ET AL EXPANSION PLUG AND INSTALLATION MEANSAND METHOD Filed Aug. 1l, 1966 DeC- 3, 1958 P. J. HUNCKLER ET ALEXPANSION PLUG AND NsTALLATIoN MEANS `AND METHOD Filed Aug. ll, 1966 2Sheets-Sheet 2 INVENTOR 75 9m J /fuNcK/.ER ml GEORGE M /'e-Fs UnitedStates Patent G 3,414,158 EXPANSION PLUG AND INSTALLATION MEANS ANDMETHOD Paul J. Huuckler and AGeorge M. Keefe, Huntington, Ind.,assignors to Hunckler Products, Inc., Huntington, Ind., a corporation ofIndiana Continuation-in-part of application Ser. No. 558,759, June 20,1966. This application Aug. 11, 1966, Ser. No. 571,941

22 Claims. (Cl. 220-24.5)

ABSTRACT F THE DISCLOSURE An aperture sealing plug, typically for engineblocks, and including a radially expandable axially extending flange,with a mechanically-operated dish shaped disc, or thermally operatedexpansive or explosive chemical component to effect the expansion in theaperture after placement therein by a finger-operated installation tool.

Background of the invention This invention relates generally to plugsemployed in engine blocks and the like, and more particularly to anexpansion plug and method for the closure of openings in such blocks.This application is a continuation-in-part of our copending applicationSer. No. 558,759 filed June 20, 1966.

In the manufacture of castings for engine blocks and for other purposes,it is common practice to provide openings at a number of locations tofacilitate removal of cores and core material used in the castingprocess. Typically these openings or holes are circular and many of themare employed in cylinder blocks for internal combustion engines.

Conventional practice is to seal such core holes or openings with steelplugs which are driven into the holes and expanded into place byhammering on them. It happens that after a period of use of the engine,one or more of such plugs become rusty and leaks develop, whereupon thecoolant from Water passages leaks from the engine cooling system. Thisnecessitates replacement of the leaking plugs.

In many instances, because of crowded conditions in engine compartments,the installation of a replacement plug is extremely diflicult and timeconsuming.

It is therefore a general object of the present invention to provideimproved expansion plugs and methods of installation thereof.

A further object is to provide plugs adapted to installation by varioustechniques which are easily employed.

Described briefly a typical embodiment of the present invention employsa generally cup-shaped first member including a dished central discportion and an axially extending flange integral therewith. The cupmember receives and retains a second dished disc, the convex faces ofthe disc portions facing each other. Expander means are provided betweenthe nearest points of the facing convex surfaces and are expanded afterinstallation of the assembly in the opening to be sealed, to achieveradial expansion of the flange.

The full nature of the invention will be understood from theaccompanying drawings and the following description and claims.

FIGURE l is a reduced scale sectional view through a liquid-containingblock having an aperture therein with a plug sealing the apertureaccording to one embodiment of the invention.

FIGURE 2 is an enlarged fragmentary section through the block showingone embodiment of the invention before expansion.

Patented Dec. 3, 1968 rice FIGURE 3 is like FIGURE 2 showing the plugassembly expanded in the opening.

FIGURE 4 is a fragmentary section of another embodiment of theinvention.

FIGURE 5 is an enlarged fragmentary section through the block showingstill another embodiment of the invention with an installation toollocating the same according to the invention.

FIGURE 6 illustrates the embodiment of FIGURE 5 after installation iscompleted.

FIGURE 7 is a section through a still further embodiment employing anexplosive cord.

FIGURE 8 is another embodiment of the invention i11- corporating achemically reactable packed compound.

FIGURE 9 is another embodiment of the invention employing an electricinitiator. f

FIGURE l0 is a view of the installation tool on a scale considerablyreduced from that of FIGURE 5, and viewing the tool looking in, thedirection of the arrow 81 in FIGURE 5.

FIGURE 11 is another view of the tool looking in the direction oppositethe arrow 81 in FIGURE 5.

Referring now to the drawings in detail, an application of a typicalembodiment of the present invention is illustrated in FIGURIE l with ablock 11 shown sche-matically containing a liquid 12 and having anaperture 13 in the wall 14 thereof. lt is desirable to seal up theaperture or opening 13, in order to prevent escape of the liquid 12 fromthe block. The pressure on the liquid may be greater than, equal to, orless than atmospheric pressure, as desired,r as the present invention isuseful in any event.

One embodiment of the plug of the present invention as illustrated inFIGURES 2 and 3 includes a generally cup-shaped member 16 having aconcavo-convex circular disc 17 with an axially extending cylindricalflange 18 extending from the perimeter of the disc. The unit is.symmetrical with respect to the axis 19. A second concavo-convexcircular disc 21 is received within the flange 18 and the outer marginaledge 22 thereof is fittingly received in the inner wall 23 ofthe flange,with the edge 24 of the flange inwardly turned to retain the disc 21within the flange. So the convex faces 26 and 27 of the discs 21 and 17,respectively, face each other.

Further according to certain embodiments of the present invention, it isdesirable to apply a separating force in a direction parallel to theaxis 19 and against these facing surfaces 26 and 27 to expand the flange18 radially outward and into tight fitting and sealing engagement withthe cylindrical wall 28 of the opening 13. For this purpose, accordingto one embodiment of the invention, an explosive charge 29 is receivedin a capsule 31 centrally located in the cavity 32 defined by the discsand flange of the plug assembly. The capsule may be formed of a materialhaving a greater wall thickness in its wall 33 than in its end walls 34,Iwall 33 being cylindrical, for example. Furthermore, the wall 34 hasits outer face 36 preferably in contact with the face 26 of disc 21throughout the entire area of the capsule face 36 to enable attainmentof good thermal conductivity between the explosive chemical charge andthe outer surface of disc 21 at 37. The capsule may be centrally locatedin the cavity 32 by a circular disc 38 of any `suitable material such asheavy paperboard or cardboard, which is both sufiicient to locate t-hecapsule in the center and yet minimizes any heat transfer from thecapsule to the flange 18 or vice versa, the perimeter 39 of the discbeing located by the inner flange Wall 23 and the central aperture 41 ofthe locator disc 38 fitting the outer surface of the wall 33 of thecapsule. Alternatively or supplementarily the capsule can be attached by`glue 42 or other means to the face 27 of the disc 17 and it may befound desirable to apply insulator means at 42 in the form of glue oranot'her insulating material to minimize heat transfer between thecapsule and the disc 17. In any event, it is desirable in thisembodiment of t-he invention to have good thermal conduct-ivity betweenthe front face of the disc 21 at 37 and the chemical charge 29 and thiscan be accomplished by using metals, and soft brass .050 inch can beused for disc 21, if desired. This material can also be used for themember 16, if desired.

By employing the construction described, the unit can be installed inthe opening 13 and the charge 29 can be exploded. by applying heatthereto. This may be done by placing a heated iron 43 against the disc21 at a point thereon near the charge which explodes the charge andcauses expansion of the capsule in an axial direction, the thicker wall33 preventingr expansion in any direction other than the axialdirection. Thus the ends of the capsule are forced away from each otherby the explosive charge and push the central portions of the discs 17and 21 away from each other. This results in radial expansion of themarginal edge 22 of the disc 21 and radial expansion of the disc 17 atits perimeter 44. This causes the flange peri-meter to expand at 44 intosealing engagement with the aperture wall 28. Radial expansion of thedisc 21 forces the flange to expand at 46 also around its perimeter toeffect a sealing engagement with the aperture wall Z3 here as well.Thus, there are at least two complete circular seals provided in theopening to prevent leakage of any liquid from the block to the exteriorthereof.

Thus it is seen from the description above, that in the illustratedexample, a line drawn between points on the discs 21 and 17 which arenearest each other would be a line on the axis of the assembly and thecapsule is constructed to permit expansion of the explosive charge inthe direction of the axis and prevent expansion in other directions.

The embodiment of the invention shown in FIGURE 4 includes a member 16constructed much like the member of the previously described embodimentbut in this example a reinforcing piece 47 may be added with a slightpiloting depression 48 at the center thereof. A disc 49 similar to disc21 is also provided but includes an internally threaded member 51 on theouter surface thereof which may be welded or brazed thereto. A centralaperture 52 is provided in the disc 49 to permit passage of thescrew 53therethrough, this screw being threadedly received in the member 51, andthe screw may have an hexagonal head thereon, for example.

In the use of this embodiment of the invention, the assembly, includingmembers 49, 16 and 53, is installed as a unit in the opening 13 in thesame manner as the other embodiment. It may be held in place andprevented from rotation by application of an end wrench or other tool tothe surface of the member 51, which can be a hexagonal nut brazed to thedisc 49. The screw S3 is then turned by applying another wrench theretowhile the first wrench is held stationary, whereby the portion of thescrew in the cavity 32 increases and the screw end bearing on thesurface 48 increases the axial distance between the central portions ofthe discs while the axial distance between their perimeters remainsconstant. This causes the radial expansion thereof in the mannerdescribed above with reference to the other embodiment of the invention.Once suicient expansion has been accom4 plished to prevent turning ofthe member 16 in the opening 13, the wrench can be removed from the nut51 and turning of the screw can continue with the other wrench appliedto the head 54 thereof. Naturally, other forms of wrench receivingsurfaces can be provided on the screw and on the threaded screwreceiver, if desired. Although it is not essential in manufacture of theassembly and before installation in an opening, it may be preferable toprovide sufficient gripping between the inwardly turned portion 24 ofthe flange 18 and the disc 49 to prevent CII member 16 from turning linthe opening during the initial expansion or turning of the screw 53. Inany event, so long as the screw can be advanced in such manner as toeffect spreading of the central portions of the discs while the portionsthereof near the perimeter thereof remain at essentially the same axialspacing, proper sealing engagement in the opening can be accomplished.

From the foregoing description, it should be apparent that a variety ofmaterials can be used in the capsule, so long as they can be activatedat a desired level of temperature to cause the axial expansion and forceapplication to one or both of the discs sufficient to obtain the radialexpansion necessary to provide a proper seal and mechanical attachmentof the assembly in the opening. It is also desirable that the materialsused in the disc and flange be permanently and plastically deformed, asdistinguished from elastic deformation, so that the axial forceseparating the centers thereof need not be maintained. This would permitthe use of truly explosive types of mixtures as distinguished from achemical composition which would expand substantially and remainpermanently expanded upon application of heat above a predeterminedlevel. Also, it should be clear that if the charge used in the capsuleis of a type which is expandable rather than explosive, the rate ofexpansion with temperature change should greatly exceed the rate ofexpansion of the materials of the discs and flanges themselves andlcapsule wall 33 in order to assure that the flange 18, for example,would not expand axially at the same rate as the charge Within thecapsule.

A variety of chemical charges could be employed, including the explosivetype and the expansion type. The specific one selected might be one inwhich a chemical reaction can be initiated by application of an electricsoldering iron to disc 21 at point 37, for example.

Although the dished form of each of the discs 17, 21 and 49 is achievedby the concavo-convex configuration in the described embodiments, thedished form might be conical or it might be a combination of shapes, solong as by being dished it is capable of radial expansion by axialloading.

The dished construction may also be used conveniently in additionalembodiments of the invention wherein the radial expansion of the dishedportion is not essential to proper functioning of the apparatus. This isrepresented in FIGURES 5 through 9 wherein a chemically expandablematerial, which can include explosives, is applied in the sealing unitso that the force of the chemical reaction is applied directly outwardagainst the axially extending ange. In the embodiment of FIGURE 5, forexample, the plug assembly 56 includes the outer member having thecylindrical flange 57 extending axially from the concavo-convex centerportion 58 with another concavo-convex disc 59 received within theflange and retained therein by the radially extending circular flange 61at the rear end of the outer member. Sandwiched between the inner member59 and portion 58 of the outer member are another concavo-convex disc 62and a sheet 63 of explosive material. A material which may be used forthe sheet 63 is flexible high explosive marketed under the trademarkDetasheet by E. I. du Pont de Nemours & Company (Inc.) of Wilmington,Del. The composition of such material may be as disclosed in UnitedStates Patents Nos. 2,992,087 and 2,999,793. Once this assembly isplaced in the opening in the manner which will be described hereinafter,the heated tip of an iron is to be applied to the disc 59 near theregion of contact at 64 between the sheet and the disc to explode thesheet and cause a direct radial expansion of the flange 57 around itsentire circumference. This will produce a tight press fit in the blockopening 13 throughout the circumference of the opening and for an areagenerally extending between the lines 66 in FIGURE 6. In this embodimentthere may be some axial separation and consequent radial expansion ofthe discs, also tending to expand the fiange.

However, the radial expansion of the axially extending flange as aresult of the direct gas pressure applied thereto by explosion of theexplosive material is emphasized in this embodiment.

Upon referring again to FIGURES 5 and 6, it will be observed that thelength of the flange and the over-all length of the plug unit from thefront to the rear is less than the thickness of the block wall at theopening 13 between the outer surface 68 thereof and the inner surface 69thereof. This makes it comparatively easy to insert the unit without thehazard of pushing it entirely through the wall and into the interior at71. However, to facilitate insertion and retention of the sealing unitproperly in the opening until it is permanently secured thereinaccording to the invention, a spring clip installation tool 72 of FIG-URES 5, l and ll is employed. This incorporates a single formed springmetal strip having two inwardly punched tabs 74 and a loop 76 therein.These tabs 74 proje-ct away from the tool faces 73 and the outer tips ofthe tabs point away from each other and away from the space between theends of the loop. The ltabs are resiliently movable toward each otherfrom their normal spacing by compression of the loop 76 between thethumb and lingers 77 and 78 of the hand of the workman. By so doing, thetips of the tabs can be inserted in the circular notch 79 formed by theinturned flange 61 of the outer member, and the disc 59. When the thumband fingers are then released, the Spring load generated in the loop byits compression urges the tab tips securely into the notch and thespring clip installing tool becomes a locator so that inward movement ofthe assembly into the block in the direction of the arrow 81 is haltedupon abutting engagement of the tool faces 73 with the block face 68.The installing tool can be left in this position until the sealing unithas been exploded in place. Then the tool can be removed easily bymerely squeezing the loop and thus retracting the tabs 74 from the notchin the sealing unit. So the loop serves both as a spring and a handle.

Another embodiment of the invention is illustrated in FIGURE 7 wherein aconstruction like that in FIGURE is employed except that the explosiveis in the form of a cord 82 wound in a circle around the convergingportions of the discs 59 and 62 and symmetrical with respect to thecylindrical axis of the cup.

In FIGURE 8, the chemically expandable material 83 is packed in thespace between the discs 59 and 62 and can be an explosive material orcan be merely a chemically expandable material so that by application ofheat thereto a chemical reaction will be caused toexpand the angeradially outward as indicated in FIGURE 6 and without reliance uponaxial separation between the disc 59 and disc 62 or central portion 58of the outer member. In this example, an aperture 84 is provided in thedisc 59 and has a varnish seal at 86 therein to prevent admission ofmoisture or contaminants during storage. However, upon application of atorch 87 thereto the flame 88 can readily melt or burn out the varnishand initiate the chemical reaction in the compound 83.

Another embodiment of the invention is illustrated in FIGURE 9 whereinthe outer cup shaped member is formed much like that of the otherembodiments but a flat disc 89 is provided within the inwardly turnedflange 61 and may be spaced from portion 58 by a washer 91 centered onthe convex surface of the inner portion 58 of the outer member. A washer92 of explosive material can be incorporated in the space 93 between the-disc portions 89 and 5S and can have a detonator cap 94 mounted thereinand extending into the aperture provided in the disc 89. Two terminals96 and 97 are available for the electrical supply to detonate the capand explode the charge to lock and seal the member in the block.

From the foregoing description, it will be recognized that various typesand thicknesses of materials can be used and various types of chemicalcharges can be employed `to obtain the degree of expansion desired andthe desired response to the type of initiator applied, whether it be bya heated iron or electrical supply or direct llame. Moreover, because ofthe convenient installation tool and the fact that the embodimentsillustrated are of less overall length than the thickness of the wall atthe opening where they are to be used, there is no danger of the unitbeing accidentally pushed into the block so far `that it falls out ofsight Where it might become a problem to proper tlow of coolant in thecase of an engine block, for example.

While the invention has been disclosed and described in some detail inthe drawings and foregoing description, they are to be considered asillustrative and not restrictive in character, as other modificationsmay readily suggest themselves to persons skilled in this art and withinthe broad scope of the invention, reference being had to the appendedclaims.

The invention claimed is:

1. A plug combination comprising:

a first member receivable in an opening to be sealed, said first memberhaving an outer portion outwardly expandable to tightly engage the wallof the opening to be sealed and said first member having an innerportion;

a second member received within said outer portion;

and expander means disposed between inner portions of said members andoperable, when actuated, to expand said outer portion.

2. The combination of claim 1 wherein said expander means includes acompound chemically responsive to application of heat to cause a rapidexpansion.

3. The combination of claim 2 wherein the inner portion of one of saidmembers has a region of high thermal conductivity, said compound beingin good heat transfer relationship with said region to facilitatesetting olf said explosive by application of heat externally to saidregion by a tool.

4. The combination of claim 2 wherein said outer portion of said rstmember is an axially extending flange and said compound is arranged toapply direct radial explosive force to said flange.

5. The plug combination of claim 1 wherein:

said first member is a disc having a ange extending axially from theperimeter of the disc, a portion of said flange being the said outwardlyexpandable outer portion of said first member;

and said second member is a disc.

6. The combination of claim 1 wherein said outer portion of said rstmember is an axiallyextending flange and said expander means includes asheet explosive disposed within said flange.

7. The plug combination of claim 1 and further comprising:

a fluid containing block having an opening in a wall thereof, said rstmember being received in said opening, with the outer perimeter of saidoutwardly expandable outer portion being disposed in contact with theperimeter of said opening, said perimeter being in plug retaining andsealing engagement in response to actuation of said expander meanswhereby said plug is permanently secured in said opening and is sealedto said opening around the perimeter of said rst member to preventpassage of liuid from within said block through said opening to theexterior of said block.

8. The combination of claim 7 wherein said outer portion is an axiallyextending circular flange the length of extension of said ange beingless than the thickness of said block wall at said opening.

9. Aperture sealing means comprising:

a iirst generally cup shaped member having a closed end insertable intoan aperture and having perimetral flange means extending axially fromsaid end;

expansion means behind said end and within said flange and operable uponexpansion thereof to move said ange radially outward throughout itsperimeter into sealing engagement with the aperture wall;

said expansion means being responsive to application of heat thereto toeffect an expansion at a rate much greater than the rate of thermalexpansion of the material of said iirst member;

and a second member mounted to said iirst member and confining the saidexpansion means within said flange. 10. An expansion plug installingtool comprising: seating means adapted to rest on an outer surface of awall of a block having an aperture through the wall;

rst and second tabs mounted on said seating means, said tabs projectinggenerally away from each other and projecting in the same direction withrespect to said seating means;

resilient means establishing a normal unloaded spacing between saidtabs:

and handle means mounted to said seating means to facilitate positioninga plug in an aperture while the plug is supported on said tabs.

1.1. The expansion plug installing tool of claim 10 wherein:

said seating means are rst and second spaced portions having facesadapted to abuttingly rest on said outer wall surface in co-planarrelationship thereto and to each other;

said tabs project to one side of the plane of said faces;

said tabs are disposed inwardly of the abutting portion of said faces;

said resilient means comprise a spring loop projecting to the side ofsaid plane opposite that to which said tabs project, said spring loopalso serving as said handle means and facilitating manipulation of theplug in the aperture.

12. The method of closing and sealing an opening in a wall of a uidcontainer, said method comprising the steps of:

placing iirst and second members as a unit in said opening;

applying an internally expanding force between said members and therebyexpanding at least one of them into locking and sealing engagement withthe wall portion of the container dening said opening.

13. The method of closing and sealing an opening in a Wall of a fluidcontainer, said method comprising the steps of:

setting a spring clip into a sealing unit:

placing said sealing unit in said opening;

properly positioning said unit in said opening by moving said springclip;

producing a chemical reaction in said sealing unit and thereby expandingsaid sealing unit into sealing engagement with the portion of said walldefining said opening and thereby sealing said opening;

and removing said spring clip from said unit.

14. The plug combination of claim 1 wherein said expander means includea thermally expansible material having a substantially greater rate ofthermal expansion than the rate of expansion of the material of saidiirst member through a predetermined range of temperature.

15. The plug combination of claim 1 wherein the inner portion of one ofsaid members is normally dished.

16. The plug combination of claim 15 wherein said expander means includea screw threadedly connected to one of said members and bearing on theother member and having a portion extending through Said `one member andaccessible for rotation by a tool receivable thereon to urge the innerportion of one member toward a lesser degree of dishing for expandingthe perimeter of the one member.

17. The plug combination of claim 5 wherein said discs are circular,said flange is cylindrical and both of said discs are dished, saidsecond disc being confined at its circumference to prevent increases inaxial separation from said first disc at its circumference.

18. The plug combination of claim 17 wherein the convex faces of saiddiscs face each other.

19. The plug combination of claim 1 wherein:

said expander means include a body having a chemical charge therein,said charge being responsive to a temperature above a predeterminedlevel t0 forceably expand, said body being constructed to permitexpansion of the charge in one direction and prevent expansion in otherdirections, and said body being oriented so that said one direction isgenerally parallel to a line drawn between points of said inner portionswhich are nearest to each other.

20. The plug combination of claim 19 wherein:

said body has a thermally conductive face portion engaging the innerportion of that one of said members which will be exposed to theexterior of the object having the opening to be sealed by said plug whensaid plug is installed therein, to facilitate attainment of saidtemperature at said charge and initiate a chemical reaction therein byapplication of a heated iron to an exposed face of the inner portion ofsaid that one member.

21. The plug combination of claim 20 wherein said chemical charge isexplosive and said inner portions are concavoaconvex, with the convexface of one inner portion facing the convex face of the other innerportion, and both of said inner portions being plastically deformed andincreasingly separated from each other upon explosion of said charge toobtain and maintain a radially expanded condition of said iirst andsecond members.

22. The method of claim 12 and further comprising the step of directingsaid internally expanding force generally parallel to an axis ofsymmetry of one of said members.

References Cited UNITED STATES PATENTS JAMES B. MARBERT, PrimaryExaminer.

